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P0781

DTC P0781 1-2 Shift

SYSTEM DESCRIPTION

DTC Detecting Condition:




The ECM uses signals from the vehicle speed sensor and direct clutch speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear). Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transmission (clutch, brake or gear etc.).

MONITOR DESCRIPTION

Monitor Strategy:




Typical Enabling Conditions:




Typical Enabling Conditions (continued):




Typical Malfunction Thresholds:




The ECM calculates the "actual" transmission gear by comparing the signals from the input speed sensor and the output speed sensor. The ECM can detect many mechanical problems in the shift solenoids, valve body, and the transmission clutches, brakes, and gears. If the ECM detects that the actual gear position and the commanded gear position are different, it will illuminate the MIL and store the DTC.

Step 1:




Step 2:




INSPECTION PROCEDURE